Name: Boletus regius
Author: sensu Thiers
Citation: California mushrooms: a field guide to the Boletes (Hafner Press 1975)
Preferred Synonyms:Butyriboletus D. Arora & J.L. Frank
Deprecated Synonyms: Boletus appendiculatus group
This taxon has been deprecated in MO without an accepted synonym because it has been replaced by a combination of three new taxa, and MO cannot synonymize Boletus regus sensu Thiers with all those taxa without also (improperly) synonymizing the new taxa with each other.
Three newly described species — Butyriboletus autumniregius, Butyriboletus primiregius, and Butyriboletus querciregius — together comprise Thiers’ (1975) concept of Boletus regius.1
1 Arora and Frank; Clarifying the butter Boletes: a new genus, Butyriboletus, is established to accommodate Boletus sect. Appendiculati, and six new species are described, Mycologia 106(3):464-480, at 478 (2014); Preliminary version published online: May 28, 2014, doi:10.3852/13-052.